Step 1: Parts list

[Needed stuff]
a 22 caliber bullet shell
2 hotwheels car wheels
2 Sequins(of the color you want)
a small nail
a small paperclip
a Q-tip(look at pic its important!)
and elmers glue
and a 1cm thick board
[Tools]
a hammer
Needle nose pliers
Wire cutters
a Ruler
And a saw
[Optional]
These Knex pieces
(these are reccomended for it to be an easy build)

Step 2: Building the body.

Step 3: Building the barrel

Step 4: The wheels

this is not the hardest part but its difficult.

Step 5: Loading and Fireing

Stick some gunpowder in it followed by a small piece of tissue then a BB. (Then i stuck a small black rock as the fuse cause i ran out of fuses)
Then take a lighter or a match and light the fuse or black rock on fire. ^.^
(the black rocks come out of fireworks)
Have fun